From 7d22857de8159ed1f815a3f262c925c9a8a202bc Mon Sep 17 00:00:00 2001
From: Luffy <lufei@apache.org>
Date: Mon, 28 Sep 2026 12:03:15 +0800
Subject: [PATCH] fix(mobile): restore day selection when reopening a trip

---
 client/src/mobile/screens/trip/MTripShell.tsx  | 12 ++++++++++--
 .../tests/unit/mobile/trip/MTripShell.test.tsx | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/client/src/mobile/screens/trip/MTripShell.tsx b/client/src/mobile/screens/trip/MTripShell.tsx
index 190761781..58d5407dc 100644
--- a/client/src/mobile/screens/trip/MTripShell.tsx
+++ b/client/src/mobile/screens/trip/MTripShell.tsx
@@ -204,7 +204,7 @@ export default function MTripShell({
   Sheets = MTripSheets,
 }: MTripShellProps) {
   const planner = useTripPlanner()
-  const { t, language, tripId, days, trip, navigate, packingItems, todoItems } = planner
+  const { t, language, tripId, days, trip, navigate, packingItems, todoItems, isLoading } = planner
 
   // Per-day colours from the dayTintProvider plugin hook — the mobile counterpart
   // of the desktop day-card wash, carried on the day chips. Empty without a plugin.
@@ -240,6 +240,14 @@ export default function MTripShell({
   // back to the first day once the whole trip is behind us.
   const seededDayRef = useRef(false)
   useEffect(() => {
+    // Re-entering the same trip from the dashboard starts with that trip's old
+    // selection still in the store. The first render treats it as seeded, then
+    // loadTrip clears it. Reset the guard with that load cycle so the freshly
+    // loaded days get their normal today/Day 1 selection.
+    if (isLoading) {
+      seededDayRef.current = false
+      return
+    }
     if (seededDayRef.current) return
     // A day that is already active counts as seeded: a later deselect is the
     // user's, and re-seeding it here would be exactly the fight this guard
@@ -250,7 +258,7 @@ export default function MTripShell({
     // Off the same helper file as the desktop day plan (#1567), so the two
     // cannot drift on what "today" means.
     planner.tripActions.setSelectedDay(findFocusDayId(days) ?? days[0].id)
-  }, [planner.selectedDayId, days, planner.tripActions])
+  }, [isLoading, planner.selectedDayId, days, planner.tripActions])
 
   // Swiping the day panel (#2051) can move the day well past the chips on
   // screen — the rail overflows from roughly six days on — so the active chip
diff --git a/client/tests/unit/mobile/trip/MTripShell.test.tsx b/client/tests/unit/mobile/trip/MTripShell.test.tsx
index 6082b038b..33f787087 100644
--- a/client/tests/unit/mobile/trip/MTripShell.test.tsx
+++ b/client/tests/unit/mobile/trip/MTripShell.test.tsx
@@ -202,6 +202,24 @@ describe('MTripShell', () => {
     expect(screen.queryByRole('button', { name: 'Sat 2' })).not.toBeInTheDocument()
   })
 
+  it('FE-MOB-SHELL-007b: re-seeds after re-entering the same trip from the dashboard', () => {
+    const { planner, rerenderShell } = renderShell()
+    expect(planner.tripActions.setSelectedDay).not.toHaveBeenCalled()
+
+    // The dashboard leaves the previous trip snapshot in the store. loadTrip
+    // clears that selection while it reloads the same trip.
+    planner.isLoading = true
+    planner.days = []
+    planner.selectedDayId = null
+    rerenderShell()
+
+    planner.isLoading = false
+    planner.days = DAYS
+    rerenderShell()
+
+    expect(planner.tripActions.setSelectedDay).toHaveBeenCalledWith(11)
+  })
+
   it('FE-MOB-SHELL-008: the back button leaves for the dashboard', () => {
     const { planner } = renderShell()
     fireEvent.click(screen.getByRole('button', { name: 'common.back' }))